The part of the radio frequency spectrum suitable for mobile and wireless services is limited and already occupied by other services in most countries. First came radio, then television, and then the mobile networks which have a growing demand for more bandwidth. Fixed Internet connections via for instance optical fibers provide plenty of capacity. Users expect wireless networks to offer the same. This is however a dilemma due to sharing of the capacity of cells comprised in the wireless network. In order to solve this dilemma, it is necessary to make smaller cells and more of them so every user can have access to the entire bandwidth of the operator without sharing it with other users. The consequence is that there will be multiple wireless networks with even shorter range than today.
Because the use of radio spectrum is auctioned by national governments it has become clear that a license for access to spectrum is a valuable resource of great importance to the entire community. This is because access to the Internet is of great national importance for the whole community with respect to settlements, infrastructure and industry. It is further not satisfactory when TV signals takes up much of the most attractive part of the spectrum without using it fully. As a consequence, major research programs all over the world have been initiated to find solutions on how the radio spectrum can be better utilized.
The lack of radio spectrum combined with a growing need for even more spectrum makes it essential to find new ways to use the spectrum. This is further emphasized by the fact that a network of radio devices connected to the Internet will in many cases consist of thousands to tens of thousands of nodes distributed over large areas, even countries. With this vast amount of different radios it is important to be able to find other radio devices to communicate with and also radio devices to coordinate traffic with.
New ways of using the radio spectrum is the subject of standardization within ETSI RRS, IEEE 802.11, IEEE 802.19, 3GPP, IEEE DySPAN and IETF. Much of this work is about how the new radio networks can share the spectrum currently used by TV signals. In the EU Seventh Framework Program FP7, there are several programs that work with co-existence between the TV and a better utilization of the dynamic spectrum. The following projects running in FP7 address new ways of using the radio spectrum: “Quality of Service and Mobility driven cognitive radio systems (QoSMOS)”, “Cognitive radio systems for the efficient sharing of TV white spaces In the European context (COGEU)”, “Spectrum and energy efficiency through multi-band cognitive radio (S acre)”, “Opportunistic networks and cognitive Management Systems for Efficient Application Provision in the Future Internet (OneFIT), and COST-TERRA.
In the United States DARPA and National Science Foundation has funded several programs on this topic. The White Spaces Coalition group plans to deliver high speed internet access to United States consumers via existing “white space” in unused television frequencies between 54 MHz and 698 MHz (TV Channels 2-51). The group includes Microsoft, Google, Dell, HP, Intel, Philips, Earthlink, and Samsung Electro-Mechanics.
Many publications support the IEEE 802.22 standard in which new WiMAX like radio networks can be established which can coexist with TV's sharing the same band, by being sufficiently far away. This is done by measuring the presence of TV transmission as described in for example US 2010/0075704 A1 or detection of other radio nodes as described in US 2010/0097952 A1. Local transmission at all radio sites can however not be detected. This is described as the “hidden node problem”.
The article: N. Ahmed, D. Hadaller, and S. Keshav, “Guess: gossiping updates for efficient spectrum sensing,” in Proceedings of the 1st international workshop on Decentralized resource sharing in mobile computing and networking, MobiShare '06, (New York, N.Y., USA), pp. 12-17, ACM, 2006, is based on distributing spectral sensing between multiple nodes as described in U.S. Pat. No. 7,738,890, US 2007/0253394 A1, and sharing information by a peer-to-peer (P2P) protocol in which spectrum sensing information by neighbor nodes for the purpose of resolving the “hidden node problem” and determine if TV transmission is present or not. This approach is different from the present invention in that it is based on effectively sharing spectral sensing information, not discovering other nodes over the Internet.
Several other patent publications like for instance US 2010/0136997 A1 use P2P in a different way than in the present invention. In the present invention P2P refers to communication between end nodes over the Internet forming a logical network or overlay. In US 2010/0136997 A1 P2P is used when there is direct communication between mobile units without using a base station like in Qualcomm proprietary technology FlashLinq which is built into its radios that allows devices to automatically discover thousands of other FlashLinq enabled devices within 1 kilometer and share a broadband connection with them. The difference between this technique and that of the present invention, is that FlashLinq uses radio, while the present invention uses Internet. FlashLinq provides direct radio connectivity between mobile terminals (user equipment) while the present invention provide communication through radios connected to Internet. Another technology is Wi-Fi Direct, which establish direct point to point links by Wi-Fi radio and therefore not related for the present invention.
Related US patent publications use dedicated control channels rather than Internet to coordinate the use of radio resources, e.g. U.S. Pat. No. 7,894,821, US 2008/0089306 A1, US 2010/0075704 A1. These claims are limited to be used within networks composed of specific nodes which is quite different from the method used in the present invention which only require a generic application running on any radio node with Internet connectivity.
The use of a transmitted beacon is a good way to determine the path loss between a transmitter and a receiver. This parameter is also commonly used for resource allocation. Beacon measurements can also be used as a method to determine which radio nodes are relevant for resource allocation as described in US 2006/0286934 A1. This is an alternative solution, but it is quite different from the method of the present invention, which determines the most relevant nodes for which coordination is performed, using the Internet and location information.
Prior art does not provide an efficient solution to the problem of efficient sharing of the TV spectrum with regards to solving the “hidden node problem” without the use of central databases which do not scale as the traffic increases.
The present invention defines a method for improved allocation of all available network resources by discovering radio nodes such as routers and wireless base stations for mobile systems, like femtocells connected to Internet. The method allows the sharing of a radio spectrum with radio nodes like TVs. By using this method, “the hidden node problem” which occurs when a transmitter disturbs a local receiver without being aware of its presence will be avoided.
The inventive method uses Internet to find the most relevant transmitters and receivers to exchange information and coordinate resources within their area to achieve an optimal utilization of the radio spectrum. The method is suitable to be implemented as a computer program performing the inventive method when run on a processor executing the different steps of the method. The processor used for this can be one that is included in small base stations. The method requires little additional use of the Internet capacity.